Steady State Speed vs Fuel Economy results

Discussion in 'General' started by seftonm, Mar 22, 2014.

  1. RedylC94

    RedylC94 Well-Known Member

    That looks like it can't, at any constant speed, touch the efficiency Gord is typically scoring .

    At what stage is energy measured for those numbers---leaving the battery, going into the motor, or where? There must be sizeable losses between the kw-hr meter used for billing (if one is charging at home) and the motor input.
     
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  2. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi RedylC94:

    Public Chargers measure the energy from the charger. There are losses going into the vehicle of course.

    The Taycan is a completely different animal when comparing to Gord's Model 3. I have never completed a Speed vs Energy Consumption with a Model 3 so I am not sure.

    Wayne
     
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  3. RedylC94

    RedylC94 Well-Known Member

    Certainly, but at what stage is power typically measured for short-term distance-energy ratios like those in your graph, or Gord's short trips? Battery output or motor input, or something else?

    Thanks!
     
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  4. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi RedylC94:

    Speed vs Fuel or energy is always measured vs the onboard storage. I cannot measure losses upstream

    The Taycan's results however show that its rated efficiency and range fall far short of actual.

    Wayne
     
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  5. seftonm

    seftonm Veteran Staff Member

    That's impressive! I've read in a few places that the Taycan's range is underrated, but it's nice to see it confirmed with your usual attention to detail.
     
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  6. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi All:

    The calibration drive consisted of 261.4 actual miles traveled vs 258.7 miles indicated from initial top off to final calibration top off.

    The Niro took almost 2-gallons more after first shutoff and maybe 15-minutes in total to top off.

    261.4 miles on 4.062 gallons = 64.35 mpg actual vs 67.4 mpg indicated resulting in a negative 4.2 percent negative aFCD offset. This is well within line of previous vehicles we have tested.

    2022 Kia Niro HEV

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    Initial top off with displays reset.

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    261.4 actual miles on 4.062 gallons top off to top off.​

    For the steady states, temps ranged from 46 to 50 degrees F with winds calm on the multiple NB and SB runs. From the calibration drive, the aFCD offset came in at 0.958 * aFCD. Only 4 of the 10 runs had a SOC difference from start to finish and I added or subtracted 1.5 mpg depending if it was a 1 bar added or 1 bar subtracted.

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    Just minutes after completing the steady states early this morning. 02:10 AM PST to be exact. ;)

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    Using straight line analysis, the EPA highway (46 mpgUS) crossover occurred at a somewhat low 64.7 mph. The larger 18s surely took the 2022 Kia Niro EX Premium to the woodshed vs the 16's on the std. Niro Hybrid trims for example. The EPA highway for the Niro EX Premium trim (67.5 mph) occurs at 42.85 mpg highway rating so 43 mpg highway is what it should actually be rated at with those larger wheels and tires.

    Wayne
     
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  7. BillLin

    BillLin PV solar, geothermal HVAC, hybrids and electrics

    I'm guessing the speed-economy curve should never have a positive slope, so the curve fitting algorithm may need tweaking given the 55/60 mph data points.

    re: wheel size - Wow. It is so cool that your testing is able to put numbers on the impact of less efficient wheels.
     
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  8. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Bill:

    I am sure if I would have taken a 4 sets of NB/SB runs between 50 and 55 mph, that slope would have been flat to slightly negative. The only time I remember seeing an actual positive slope was on a 2017 (???) Camry V6 w/ a 6-speed AT we tested way back with an increase of a mpg or two between 50 and 55 mph.

    Whenever I see a Monroney with the larger "premium" wheels arrive, I cringe. :(

    2022 Kia Niro EX Premium Hybrid Monroney

    [​IMG]

    Wayne
     
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  9. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi All:

    Another all-electric that performed extremely well on the CleanMPG Speed vs FE charts.

    2022 AWD Audi GT RS with an 84 kWh useable battery and 21" summer Goodyear F1 Performance tires (232-miles AER) EV Calibration Drive

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    Topped off…

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    Reset (0.0 miles/KWh) to 3.8 miles/kWh over 300.3 miles indicated, 303.3 miles actual.

    But first, the Audi's DCFC spec is 5 to 80% in 22 to 23-minutes but just like the Porsche Taycan, 5 to 80 percent occurred in a staggeringly fast 19-minutes! Whatever SW updates the VW Group has done to the Porsche has also been uploaded into the Audi and it kicks @$$. :D

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    88 KWh from 5 to 100% SOC indicates it would take ~ 92 KWh to charge from 0 to 100%. If the maximum actual useable pack capacity is 84 KWh, this indicates a charging efficiency of just 91.3 percent. I thought it would have been higher. Or that more than 84 KWh is useable? A Question I have not found an answer too.

    In any case, 303.3 miles (actual) on 88.15 KWh = 3.44 mi/kWh. If the actual pack charge was 84 KWh * .95 (5 to 100%) or 79.8 KWh added to the pack and not lost to heat from the cable to the Inverter to the pack, this would indicate 303.3 miles/79.3 KWh = 3.82 Miles/KWh which is almost exactly what the Audi display indicates at 3.8 mi/KWh. I used a 0 percent offset for that Speed vs Energy Economy curve.

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    The EPA highway rating of 2.43 miles/kWh was deduced from the Audi GT RS’ EVs 82 MPGe highway/33.7 kWh/gal.

    79/82 MPGe (city/highway)/33.7 kWh/gal = 2.34/2.43 MPGe (city/highway)

    Temps from 52 to 54 degrees F, Winds calm.

    The EPA highway crossover (2.43 mi/KWh) occurred at 73.375 mph. Compared to its EPA rating at 67.5 mph = 2.82 mi/KWh, this indicates the EPA range highway should be 271-miles, not 232-miles from the combined number.

    When comparing the above graph of the AWD 22 Audi GT RS with the 21" wheels and sticky summer performance Goodyear F1s vs the RWD Taycan with 19" Continental ProContact All-seasons, the efficiency fall off is poignant!

    Consider both vehicles efficiency at 70 mph.

    RWD Porsche Taycan w/ All-season 19s - 3.12 mi/KWh
    AWD Audi RS GT w/ Summer Performance 21s - 2.7 mi/KWh

    The efficiency fall off is 15.5%!

    While not nearly as efficient as the 2021 RWD Taycan w/ 19’s and all-seasons, the AWD GT RS is a bit more efficient than its 2.32 miles/kWh rating around town as well.

    Wayne
     
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  10. thunderstruck

    thunderstruck Super Moderator

    Couple of things of interest on my new one. The car will shut the ICE off when CC is on, unlike my 2016 Prius would do. TCH seems to want to settle at 1280 RPM which again rings a bell. It also will drop a lot on the back road here which is rated at 55 MPG down to 992 RPM but with ICE using 0 GPH. Engine defuels but does not shut off for some strange reason. Then all of a sudden it shuts off. I need more seat time and more eyes on SG before I can figure this thing out.
     
  11. litesong

    litesong litesong

    Wayne posted:……..Goodyear F1 Performance tires

    litesong posted: I’ve got 2 free used Goodyear F1 tires (with quite a bit of rubber) to eventually use on our Hyundai Elantra. So we’ll see how they work. I’ve already had 4 free used tires that worked smoothly & quietly on our cars.
     
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  12. RedylC94

    RedylC94 Well-Known Member

    Coincidentally or not, those are exactly the same speeds my Prius engine favors when warming up, and when coasting with fuel cut off at more than about 45 mph, respectively. Minimum engine speed when it's producing any power (typically during slowish steady forward speed on a level stretch) is slightly slower, but harder to pin down.
     
  13. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi All:

    2022 RWD Kia EV6s Speed vs Energy Economy.

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    The EPA highway rating of 3.00 miles/kWh was deduced from the Kia EV6s 134 MPGe highway/33.7 kWh/gal.

    134/101 MPGe (city/highway)/33.7 kWh/gal = 3.98/3.00 MPGe (city/highway)

    Winds were calm and the temp was an unwavering 68 degrees F for the entire 2.5-hour period to record the speeds and energy economy data. With an EPA highway of 3.0 miles/KWh, the EPA highway crossover occurred at an excellent 80 mph using a straight line analysis, second only to the record setting Taycan's 84 mph. Indicated speed matched actual for all recorded speeds at 50, 55, 60, 65, and 70 mph.

    The EPA highway crossover (3.00 mi/KWh) occurred at 73.375 mph. Compared to its EPA rating at 67.5 mph = 2.82 mi/KWh, this indicates the EPA range highway should be 271-miles, not 232-miles from the combined number.

    Wayne
     
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  14. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi All:

    The 2024 Toyota Corolla Cross Hybrid in SE trim and equipped with the optional, fuel derisive 18" alloys, is next up...

    The calibration drive consisted of 233.0 actual miles traveled from initial top off at a Costco in Vista, CA to the final calibration top off at a Costco in Corona, CA.

    2024 Toyota Corolla Cross Hybrid

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    Topped off with displays reset.

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    60.3 mpg over 233.0 miles indicated.​

    The refuel came in two batches as the pump timed out when I snapped the pic of the Corolla Cross Hybrid at the Costco pumps. 2.838 + 1.090 gallons = 3.928 total gallons.

    And the odometer offset? It proved to be insignificant with 120.0 miles traveled vs 119.9 miles indicated. The .1 miles came from me walking around parking lots with my phone trying to get a nice shot of the Corolla Cross Hybrid in front of the San Bernardino Mountain Range. Nothing worthwhile was in the offing on this little drive but I did get one in front of the P-51 Redtails plane at the Proud Bird Restaurant just outside of LAX in Los Angeles.

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    Trip A and aFCD reset for a short 120.0-mile odometer study...

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    233.0 actual miles/3.928 gal = 59.318 mpg actual vs 60.3 mpg indicated.

    The aFCD offset: 59.3/60.3 = 0.983

    For the steady states, temps ranged from 60 to 62 degrees F with winds calm on the multiple NB and SB runs. From the calibration drive, the aFCD offset came in at 0.983 * aFCD. Only 4 of the 10 runs had a SOC difference from start to finish and I added or subtracted 2.0 mpg depending on if it was a 1 bar added or 1 bar subtracted.

    The speedometer was 1 mph faster than actual from 50 to 70 mph. Meaning 50 mph actual was 51 mph indicated on the speedometer, 55 mph actual was 56 mph indicated, 60 mph actual was 61 mph indicated, 65 mph actual was 66 mph indicated, and 70 mph was 71 mph indicated. CC however matched the actual but not the indicated. CC set at 70 mph, actual was 70 mph while indicated was 71 mph for example.

    2024 Toyota Corolla Cross Hybrid SE

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    Ready for steady states but only after a southern California, Pacific Coast sunset. ;)

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    Using straight line analysis, the EPA highway (38 mpgUS) crossover occurred at an excellent 70.75 mph. And this is while equipped with the optional and larger 225/55R18 from the XSE which probably knocked off at least 2.5 mpg from its results vs the std. S and SE equipped with the 215/65R17s. Good job Toyota.

    I completed a 75 mph back and forth run because someone asked, and it came in at 36.2 mpg actual including the offsets.

    Wayne
     
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  15. litesong

    litesong litesong

    P-51 Redtails plane a


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    Wayne[/QUOTE]

    For decades down near the docks in Everett, WA, a P-40 was mounted right on the roof of a small gas station

     
    Last edited: Jun 24, 2024
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  16. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi All:

    I have to add all of the refueling and aFCD offset detail plus odometer study but the 2024 Lexus NX 450h + with the Toyota PHEV hybrid drivetrain performed way beyond its 38/33 mpgUS city/highway rating. Since this was a last minute addition to our review vehicle lineup, I did not even know the EPA ratings as there was no Moroney in the glovebox. When I looked it up, I was shocked at how low it was vs the results attained. The EPA of just 38/33 mpgUS city/highway show an EPA highway (33 mpgUS) came at an astonishing 76.1 mph! If I would have known the NX 450h + blew out its EPA highway by that much, I would have completed a 75 mph steady state too. Better yet, compare these results with the Corolla Cross Hybrid directly above. The 303 hp total output 2.5L PHEV out of the RAV4 Prime provides nearly the same steady state efficiency results as the all-new 2.0L Hybrid drivetrain in the Corolla Cross HEV!

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    In detail, the odometer study looks like this: 62.3 miles indicated vs 64.3 miles actual yielding an Odometer offset of 1.032

    The aFCD study yielded 52.9 mpg after 94.5 miles indicated. With the Odometer offset, the actual miles of 97.5 miles on 1.843 gallons = 52.9 mpg actual which matched the aFCD. Rarely do we see a 1.00 offset.

    I will add the documentation pics later as I have to get a last few shots before the Press Fleet handlers come pick it up in a few hours.

    As promised...

    The Calibration and Odometer study for the 38/33/36 mpgUS city/highway/combined rated 2024 Lexus NX 450h +.

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    Topped off and displays (aFCD and Trip B) reset at a Costco in Carlsbad, CA.

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    Measured fill in progress at the same Costco in Carlsbad, CA the following morning.

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    52.9 mpg indicated after 94.5 indicated miles on 1.843 gallons.​

    The Odometer study...

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    62.3 miles indicated and 64.3 miles actual = +1.032 offset.​

    All-in, 94.5 miles * 1.032 = 97.524 miles/1.843 gal = 52.9 mpg vs the 52.9 mpg indicated.

    Rarely do we receive a 0.00 offset but here it is.

    Wayne
     
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  17. litesong

    litesong litesong

    Yes, like I said in the other thread, they need the car for the new advertising campaign for the "Lexus NX 450h Garden Transformer". :rolleyes:
     
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  18. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi All:

    Publishing the Speed vs FE of the 2023 Toyota Prius LE from last May with the GWR aFCD offsets. Those 17s provide a world of difference vs the XLE we had a few months back. My only caveat is that the LE was setup extremely well - 10k miles, fresh oil change, and tires pressed up vs the XLE we tested a few months back.

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    Temps ranged from 63 to 64 degrees F and winds were calm for the northbound and southbound drives while the aFCD offset came in at 1.002 vs actual (fuel fill and odometer offset) for each of the 10 back and forth runs. The Odometer offset came from 2,648.7 actual miles vs Trip A at 2,596.3 miles. The aFCD offset was deduced from the 2,648.7 actual miles traveled on 27.883 gal = 95.2 mpg actual vs 95.0 mpg indicated.

    The EPA highway crossover speed (56 mpg highway) occurred at an exceptional 74.9 mph. This indicates this well setup 2023 Prius LE with the 17s 56 mpg highway rating is more than solid and they could have published a 60 mpg EPA highway rating.

    Wayne
     

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